Predicate the full screen 1080p and 4k resolution?

[Mike-the-one]

So how do I tell the best supported full screen 4k and 1080p resolution? I know I can use 1920x1080 and 3840 x 2160, but nowdays, most phones are wider, I want to go full width.
One theory I have is, query the display resolution, so I can get the aspect ration, then do the math to find the corresponding 1080p resolution and 4k resolution.

for example, for pixel 9 pro, the display is 2856x1280, after the math, it is 2410x1080
for pixel 8 pro, the display is 2992 × 1344, after the calculation it is 2404x1080

they seem to work for both streaming and recording.
however if I want to record to 4k, double the width and height do not work, I have to use standard 16x9 4k.
So how to record in full screen 4k?

thanks

[pedroSG94]

Hello,

If you have the calculation using 1080 (2410x1080) you can use a simple math again to get the 4k the same way.

X = 2160*2410 / 1080 = 4820

Result: 4820x2160

The problem here is that maybe this resolution is higher than your max resolution supported. In that case you can calculate it this way.

If my max size supported is 3840 (width of 4k). You can get height using the aspect ratio:

H = 1080/2410 * 3840 = 1720

Result: 3840x1720

[pedroSG94]

Anyway, if you are recording the screen. It is not worth it and the quality is not better because you are scaling the image.

I think that you should stream or record max to the device screen resolution.

[Mike-the-one]

Thanks! so the encoder and youtube or any rtmp server they are ok with these random resolution?

[pedroSG94]

Hello,

rtmp servers should support it. In the case of YouTube or others platforms that also have a player to reproduce the stream. Keep in mind that the player resolution is always 16:9 so the stream in the player will have black borders similar to if you stream using 16:9 in my app side.

[Mike-the-one]

@pedroSG94 thanks!
You mentioned that think that you should stream or record max to the device screen resolution.
so I am using camera2 source and filters so the resolution won't go beyond the screen resolution? I thought if camera is capable of 4k e.g. 3840x2160 then I should be able to stream and recording in 4k? or it is because of the filters so that we are actually stream/record the camera preview rendered with filters, so that the resolution is limited to screen resolution?

Thanks

[pedroSG94]

Aaah, I thought you was using Screen source as video source. If you are using camera2 I recommend you use any resolution provided by Camera2Source methods (getBackCmeraResolutions method?

[Mike-the-one]

Yes I tried that but it returns these for Pixel 8Pro:

val  camera2Source = genericStream.videoSource as? Camera2Source
val list = camera2Source?.getCameraResolutions(CameraHelper.Facing.BACK)

0 = {Size@38488} "176x144"
1 = {Size@38489} "320x240"
2 = {Size@38490} "352x288"
3 = {Size@38491} "640x480"
4 = {Size@38492} "1280x720"
5 = {Size@38493} "1280x960"

According to Google, Pixel 8 pro can do 4K at 60fps. But I don't even see 1080p from the list.

[pedroSG94]

Hello,

That is really weird. Are you using a physical pixel 8 pro or emulator?

[Mike-the-one]

emulator

[pedroSG94]

That is the problem, an emulator is not a real pixel 8 pro. It is only a virtualized device with a generic room and the screen resolution of 8 pro.

Using an emulator, that output is correct.

[Mike-the-one]

Thanks! Yes indeed, connected to a real S20FE ( I don't have pixel 8 pro) it shows many more resolutions

0 = {Size@34449} "4032x3024"
1 = {Size@34450} "4032x2268"
2 = {Size@34451} "4032x1816"
3 = {Size@34452} "3024x3024"
4 = {Size@34453} "1920x824"
5 = {Size@34454} "3840x2160"
6 = {Size@34455} "1920x1080"
7 = {Size@34456} "2400x1080"
8 = {Size@34457} "1920x864"
9 = {Size@34458} "1920x1440"
10 = {Size@34459} "1440x1080"
11 = {Size@34460} "1088x1088"
12 = {Size@34461} "1280x720"
13 = {Size@34462} "960x720"
14 = {Size@34463} "720x480"
15 = {Size@34464} "640x480"
16 = {Size@34465} "640x360"
17 = {Size@34466} "352x288"
18 = {Size@34467} "320x240"
19 = {Size@34468} "256x144"
20 = {Size@34469} "176x144"

So I did a test, set the streaming resolution 2400 x 1920, and recording 4800x2160, and it worked, and I inspected the mp4 in quick player and it shows the resolution is 4800x2160... but the this resolution is not supported by the back camera, so why it worked?

[pedroSG94]

It is because your device open the camera to a resolution close to that and rescale it.
But not all devices can do it so I recommend you limit the resolution to the higher resolution of your device.

[Mike-the-one]

@pedroSG94 Thanks